Flexible pipe for high pressure

ABSTRACT

A flexible pipe ( 10 ) for high pressure is provided with a sublayer ( 11 ) made of natural or synthetic rubber or man-made polymers in general, and with a first and a second stiffening layer ( 12, 14 ), which are superimposed and both consist of a high-resistance metal spiral, whereby the spiral can have one or more wires. Between the first ( 12 ) and the second ( 14 ) layer there is interposed a skim coat ( 13 ) made of natural or synthetic rubber or man-made polymers in general. The flexible pipe ( 10 ) for high pressure is also coated with a coating ( 15 ) made of natural or synthetic rubber or man-made polymers in general.

[0001] The present invention relates to a flexible pipe for highpressure.

[0002] Flexible pipes for high pressure are widespread, and they areused to transport oil or hot water or other fluids.

[0003] The present invention will make particular reference toapplications of a flexible pipe for high pressure to oil transport forthe hydraulic actuation of lift trucks, or to applications of a flexiblepipe for transporting or conveying water in pressure in industrial watercleaning machines. In all cases, the pipe of the invention can be usedfor other uses besides those mentioned above.

[0004] In particular, for these purposes, pipes provided with a sublayermade of natural or synthetic rubber or manmade polymers in general areknown, on which one or two stiffening plaits are applied to form as manysuperimposed layers.

[0005] Stiffening plaits are separated from each other by a skim coatmade of natural or synthetic rubber or manmade polymers in general;moreover, such flexible pipes are coated with a coating made of naturalor synthetic rubber or man-made polymers in general.

[0006] Plaited flexible pipes of the described type can be subject tovarious problems, among which an excessive thickness that causesundesired dimensions, and a bending radius that is not alwayssatisfactory.

[0007] Thus, purpose of the present invention is that of realising aflexible pipe for high pressure that should maintain a high flexibilityand lightness degree, as well as minimum overall dimensions, even thoughbeing capable of standing high operating pressures.

[0008] Another purpose of the invention is that of realising a flexiblepipe for high pressure that should be simple and inexpensive to realise.

[0009] These and other purposes are reached by a flexible pipe for highpressure according to claim 1, to which reference shall be made forshortness.

[0010] Further features of the invention are defined by the other claimsattached to the present invention.

[0011] Further features and advantages of the present invention willappear more clearly from the following description and attached drawing,provided by way of an explicative and non-limiting example. In suchdrawing:

[0012]FIG. 1 shows an exploded axonometry view of a flexible pipe forhigh pressure, according to an embodiment of the present invention.

[0013] With particular reference to the mentioned figure, the flexiblepipe for high pressure according to an embodiment of the presentinvention is globally indicated with reference numeral 10.

[0014] The flexible pipe for high pressure 10 exhibits a sublayer 11made of natural or synthetic rubber or man-made polymers in general, afirst layer 12 consisting of a high-resistance steel spiral, and asecond layer 14, also realised with a high-resistance steel spiral. Inparticular, spirals can have one or more wires. The spirals of the firstand of the second layers have an opposite direction.

[0015] The first layer 12 and the second layer 14 are superimposed, anda skim coat 13 is arranged between them, preferably made of natural orsynthetic rubber or man-made polymers in general.

[0016] Moreover, the flexible pipe for high pressure 10 is coated with acoating 15, also preferably made of natural or synthetic rubber orman-made polymers in general.

[0017] It must be noted that the flexible pipe 10 is particularlyadapted to allow the transport of oil or water in pressure, or of otherfluids in general.

[0018] In particular, the flexible pipe 10 can be advantageously usedfor transporting oil for the hydraulic actuation of lift trucks, or fortransporting or conveying water in pressure in industrial water cleaningmachines.

[0019] With the flexible pipe 10 according to the present invention itis possible to reach bursting pressures of over 1200 bars.

[0020] The bending radius obtained with the flexible pipe 10 accordingto the present invention is less than that of plaited pipes having thesame diameter.

[0021] The features of the flexible pipe for high pressure object of thepresent invention, as well as its advantages, clearly appear from theabove description.

[0022] The following conclusive remarks and comments are intended tobetter and more clearly define the above advantages.

[0023] In the first place, the flexible pipe for high pressure accordingto the present invention is more flexible with respect to traditionalplaited pipes.

[0024] Moreover, the pipe of the invention has better performances withrespect to two-plait pipes since it is lighter and more flexible, inparticular with reference to its resistance to pressure.

[0025] Moreover, it is less expensive, in particular due to the factthat through the use of spiralling machines, a higher productivity isobtained since the spiralling operation is faster than the plaitingoperation.

[0026] Finally, it is clear that several variants can be made to theflexible pipes for high pressure, object of the present invention,without departing from the novelty principles of the inventive idea.

[0027] In the practical embodiment of the invention, the materials,shapes and sizes of the illustrated details can be of any type accordingto the requirements, and the same may be replaced with other technicallyequivalent details.

[0028] The scope of the invention is defined in the claims attached tothe present application.

1. Flexible pipe (10) for high pressure, of the type provided with asublayer (11) which defines a passage section for a fluid in pressure,and with a first and a second stiffening layer (12, 14), characterisedin that the above first and second stiffening layers (12, 14) consist ofa high-resistance metal spiral.
 2. Flexible pipe (10) according to claim1, characterised in that between the first (12) and the second (14)stiffening layer there is interposed a skim coat (13) made of natural orsynthetic rubber or man-made polymers in general.
 3. Flexible pipe (10)according to claim 1, characterised in that it is coated with a coating(15) made of natural or synthetic rubber or man-made polymers ingeneral.
 4. Flexible pipe (10) according to claim 1, characterised inthat t he above spiral relating to the first (12) and second (14)stiffening layers is made of high-resistance steel.
 5. Flexible pipe(10) according to claim 1, characterised in that the above sublayer (11)made of natural or synthetic rubber or man-made polymers in general. 6.Flexible pipe (10) according to claim 1, characterised in that the abovefluid in pressure is oil or water or other fluids in general. 7.Flexible pipe (10) according to the previous claims, characterised inthat it can reach bursting pressures over 1200 bars.
 8. Flexible pipe(10) according to the previous claims, characterised in that it is usedfor transporting oil for the hydraulic actuation of lift trucks, or fortransporting or conveying water in pressure, in industrial watercleaning machines.